Graph traversal is a core operation that is used in many graph processing applications. It involves visiting all nodes in the graph at most once in a particular order. The traversal procedure is typically performed in distinct steps where nodes at a particular level could be discovered in any order. Breadth-First Search (BFS) and Depth-First Search (DFS) are common examples of graph traversal.
Some of the applications of graph traversal are finding all reachable nodes (for garbage collection), finding the best reachable node (single-player game search), finding the best path through a graph (for routing and map directions) or topologically sorting a graph.